This invention relates generally to deployment of sensors within a surveillance area, and more specifically, to systems and methods for controlling a landing position of ground sensors deployed from an air vehicle.
To provide surveillance for an area, sensing devices of various forms are typically placed in some desired pattern on the ground to sense the presence of, for example, people, animals, and vehicles, commonly referred to herein as intruders, within the area. In addition to detecting the presence of intruders, other applications utilizing various sensors include one or more of identification, location, speed of travel, and travel direction of such intruders. The purpose in at least some of these applications includes one or more of military threat detection, statistical data gathering, security purposes, for example, for intruder detection in and around nuclear power plants, aircraft parking areas, water supply systems, and private property to name a few.
To provide the desired surveillance, the sensing devices typically incorporate one or more of several sensor types. The various sensor types are operable for, for example, vibration sensing, acoustical sensing, magnetic sensing, temperature sensing, and additionally, GPS functionality to provide location data for each individual sensing device. With a location of each individual sensing device known, and through communication from individual sensing devices to a common base station, triangulation utilizing the sensing devices provides a capability to locate the source of the sensed parameter. Locations are typically provided in latitude and longitude coordinates.
In certain deployments, due to accessibility issues, the sensing devices are deployed by launching or dropping the sensing devices from an air vehicle. The sensing devices for such deployments are configured with a weighted leading edge having a point. It is hoped that conditions during the descent of such devices will allow the point to eventually penetrate the ground providing a particular orientation for the individual sensors within the sensing device and allow the device to be self supported in an upright orientation.
The unguided nature of these sensing devices, however, sometimes results in ground deployment location errors, and orientations other than a desired orientation. These location and orientation inaccuracies result in a relatively large number of the deployed sensing devices being unusable, or at least providing inaccurate information from one or more of the individual sensors within the sensing device.